This invention relates to oiling systems, and especially to oiling systems as used in rotor assemblies, for example rotor assemblies of air cycle machines. Oiling requirements are relatively severe in connection with the bearings of a rotor shaft of turbomachinery. Lubrication requirements are relatively easily met and can survive lack of uniformity in oil flow and reductions in supply. It has become increasingly apparent, however, that the shaft bearings are repositories of heat coming from external and internal sources, which heat is best dissipated by maintaining a full, generous flow of oil through the bearings. In the prior art, oil has been supplied by wicking devices which provide a movement of oil sufficient for lubrication purposes but totally inadequate to proper cooling. A use of capillary means to start or to prime an inherent pumping system has been proposed. Results, however, have been inconsistent, particularly at relatively high oil temperatures, due at least in part to a concept of structure which brings capillary devices as close as possible to the rotor shaft. A use of separate oiling pumps and the like has been suggested but this is a relatively costly recourse which may be impractical for structural reasons.
A high speed rotor shaft is inherently subject to vibrating and gyrating influences which can become sufficiently severe to lead to damage and malfunction of the rotor system. It has heretofore been sought to avoid or to minimize such influences by constructing the rotor assembly with such high degree of precision that movements of the rotor are very closely confined and controlled by mechanical means. Obviously this has involved relatively costly and skilled machining and assembly procedures.
Insofar as is known, these problems of the prior art have not been adequately dealt with heretofore. Practices as described in the foregoing constitute the closest, most pertinent known prior art.